test_search.py 文件源码

def test_parameters_sampler_replacement():
    # raise error if n_iter too large
    params = {'first': [0, 1], 'second': ['a', 'b', 'c']}
    sampler = ParameterSampler(params, n_iter=7)
    assert_raises(ValueError, list, sampler)
    # degenerates to GridSearchCV if n_iter the same as grid_size
    sampler = ParameterSampler(params, n_iter=6)
    samples = list(sampler)
    assert_equal(len(samples), 6)
    for values in ParameterGrid(params):
        assert_true(values in samples)

    # test sampling without replacement in a large grid
    params = {'a': range(10), 'b': range(10), 'c': range(10)}
    sampler = ParameterSampler(params, n_iter=99, random_state=42)
    samples = list(sampler)
    assert_equal(len(samples), 99)
    hashable_samples = ["a%db%dc%d" % (p['a'], p['b'], p['c'])
                        for p in samples]
    assert_equal(len(set(hashable_samples)), 99)

    # doesn't go into infinite loops
    params_distribution = {'first': bernoulli(.5), 'second': ['a', 'b', 'c']}
    sampler = ParameterSampler(params_distribution, n_iter=7)
    samples = list(sampler)
    assert_equal(len(samples), 7)